This invention relates to a refrigeration compressor with a driving electric motor mounted in the same housing. In the past, it has been conventional practice to mount the compressor and the motor in a single hermetically sealed housing in an arrangement providing for circulation of incoming vapor through the electric motor for purposes of cooling the motor before the vapor is drawn into the compressor. Generally speaking, it is desirable to supply intake vapor from the evaporator to the compressor at a temperature as low as possible. When the intake gas is supplied to the compressor through the electric motor, the heat transferred to the vapor in cooling the motor elevates the temperature of the intake vapor supplied to the compressor. In order to supply intake vapor to the compressor at low temperature, it is desirable to supply intake vapor from the evaporator directly to the compressor inlet and to take the heat out of the motor without utilizing intake vapor between the evaporator and the compressor.